The invention pertains to a transport device with a transfer device for transferring goods from a delivering conveyor to a discharging conveyor and a method for operating such a transport device.
In the production of cans, tubes and bottles, these goods are transported from workstation to workstation on so-called chain pins. In production lines for goods of this type, the utilization of transfer devices is required because it is not possible to use transport trains of arbitrary length, wherein several transport chain modules that respectively comprise a transport chain with chain pins are used instead such that the transfer of the goods from transport chain to transport chain is absolutely imperative. The transfer devices used usually consist of so-called vacuum drums that remove the goods from a delivering conveyor comprising chain pins and then place the goods on a discharging conveyor comprising chain pins. A transfer device of this type is described, for example, in DE 10 2009 029 778 A1 of the applicant. The disadvantage of known transfer devices can be seen in that a continuous transfer of goods requires a significant deceleration of the discharging conveyor in order to compensate gaps between the goods on the delivering conveyor. This respectively limits the maximum transfer speed and the operating speeds of the conveyors because the discharging conveyor cannot be arbitrarily decelerated and accelerated due to its large inert mass. In addition, significant speed changes of the conveyor result in substantial wear and also entail the risk of losing goods off the chain pins elsewhere due to the jerky motions.
A transport device known from DE 10 2010 029 519 A1 features a transfer device comprising an endless transport element with a first and a second section that can be operated with different speeds, wherein this causes a carriage carrying the endless transport element to be horizontally deflected. The known transport device serves for coupling a continuously operating machine and a cyclically operating machine to one another, wherein the displacement of the carriage makes it possible to alternately generate and once again compensate a throughput loss in dependence on the cycle. In the known device, the first drive for driving the first section intended for receiving continuously delivered goods is mechanically coupled to the continuously operating delivery device, i.e. the speed of the first section of the endless transport element always inevitably corresponds to the speed of the delivering conveyor. A compensation of gaps therefore cannot be realized with the known transport device and is also not mentioned as a problem in this document.
EP 1 721 844 B1 discloses a transport device, in which a displaceable transfer star is arranged between two endless transport elements. The two endless transport elements do not feature sections that are driven with different speeds.
A device without transfer carriage is known from EP 1 375 394 B1, as well as from DE 2 006 665 A1.
Based on the above-described prior art, the invention aims to disclose an improved transport device for transferring goods from a delivering conveyor, particularly with chain pins, to a discharging conveyor, particularly with chain pins, which allows higher maximum speeds of the conveyors and at the same time ensures a largely accurate and continuous transfer of goods. The invention furthermore aims to disclose a method for operating the transport device.